@Belter speech developed from the many languages carried into the Belt by early workers and settlers.
There is no single universal Belter language. Instead, stations and communities use numerous related dialects that blend vocabulary, gestures, technical terminology, and expressions from cultures of @Terra and @Mars.
Hand signs and body language are particularly important. Early workers needed to communicate through helmet visors, across noisy machinery, and in environments where radio contact could not be trusted. Many gestures remain common even when spoken communication is available.
Belters frequently change how they speak depending on their audience. A trader may use formal Terran vocabulary during negotiations, station slang among friends, and an entirely different dialect with family.
Inner-worlders sometimes dismiss Belter speech as crude or uneducated. In reality, it can communicate technical conditions, social relationships, and environmental dangers with remarkable precision.